The invention relates to apparatus for the production of various construction materials, and more specifically, to apparatus for dehydration of continuously fed flow of a suspension, such as suspensions of cement slurry, ceramic dross and other finely divided aqueous suspensions. The invention may be most successfully used in various branches of the chemical industry and in metal production.
At present, there are widely known apparatus for dehydration of finely divided viscous suspensions using filtering, such as vacuum filters and filter presses. Vacuum filters comprise discs or drums having a filtering surface. Filtering in vacuum filters is effected by evacuating liquid from the suspension when the filtering surface is immersed in the suspension. A layer of dehydrated material is formed on the filtering surface which is referred to as cake.
Filter presses also comprise filtering surfaces. Filtering in the filter presses is effected by compressing the suspension between the filtering surfaces. The cake is also formed in this case.
Known apparatus are, however, very complicated in structure, they feature high metal consumption for their manufacture, exhibit large filtering surface area and high power requirements.
The above disadvantages are partially eliminated in the apparatus described in USSR Inventor's Certificate No. 309917.
In this apparatus, the suspension is dehydrated by combining vacuum and vibration actions. The apparatus has a vertical container provided with a pipe for feeding starting suspension at the top thereof and with a pipe for discharging thickened suspension at the bottom thereof. The vertical container is made converging in the direction of the suspension flow, and the side walls are made as filtering surfaces. The suspension being filtered flows through the inner space of the container between the filtering side walls, the inner space accommodates a vibrator immersed in the suspension. The vertical container is arranged in a chamber under reduced pressure. Under the action of vibration, the suspension is liquefied, and liquid phase is released therefrom due to reduced pressure to pass through the filtering walls.
This apparatus is simple in structure, it does not take much metal for construction, has a small filtering surface area and does not require much power.
It is, however, noted that with continuous operation of the apparatus, meshes of the filtering surface are clogged with solid particles due to insufficient regenerating action of vibrations. As a result, the filtering rate decreases and the degree of dehydration of suspension is lowered.
It is an object of the invention to eliminate the above disadvantages.
The main object of the invention is to provide an apparatus for dehydration of a continuously fed flow of suspension having a construction which eliminates clogging of meshes of the filtering surface.
Another object of the invention is to provide an apparatus for dehydration of a continuously fed flow of suspension in which the filtering rate is increased and degree of dehydration is improved.
These and other objects are accomplished due to the fact that in an apparatus for dehydration of a continuously fed flow of suspension comprising a vertical container which has pipes for feeding a suspension and for discharging a thickened suspension, respectively, and which is made converging from the top down and has filtering side walls for the passage of filtrate, a vibrator and a pipe for discharging filtrate, wherein, according to the invention, the vibrator is mounted outside the container and has vibration transmitting planes extending substantially along the filtering side walls in such a manner that they cooperate, during operation of the vibrator, with the filtering side walls to impart vibrations thereof.
This arrangement of the vibrator and its vibration transmitting planes enables the transmission of vibrations to the filtering side wall of the container. This facility provides for the effect of self-regeneration of the filtering surface, that is its continuous cleaning from solid particles of suspension so that continuous dehydration of suspension may be effected without cake formation which, in turn, provides for greater degree of filtering and higher filtering rate.
According to one embodiment of the invention, the vibration transmitting planes of the vibrator are arranged directly adjacent to the filtering side walls of the container and extend in parallel therewith.
This arrangement of the vibration transmitting planes enables an efficient transmission of vibrations along the entire length of the filtering surface of the wall without damaging it.
Longitudinally extending grooves are preferably provided in the vibration transmitting planes of the vibrator opposite to the filtering side walls to ensure most rapid flow of filtrate down the planes.
According to another embodiment of the invention, in case the container is formed by a cylinder having a solid wall and a truncated cone arranged coaxially therewith and mounted within the cylinder which is made of a filtering material to form the filtering side walls of the container, the vibration transmitting planes of the vibrator are provided inside the truncated cone along the height thereof and rigidly secured thereto, the truncated cone terminating, at the bottom, in a pipe for discharging filtrate.
Rigid connection of the truncated cone to the vibration transmitting planes enables uniform distribution of vibrations over the entire filtering surface thereof irrespective of the density of the suspension flow which varies along the height of the container.
The invention is further characterized in that the filtering side walls of the container are made of a woven material which exhibits sufficient flexibility for taking up vibrations.
The filtering side walls of the container are preferably inclined to the vertical axis thereof at an angle from 1 to 7.5.degree. so as to provide for desired velocity of flow of filtrate through meshes of the filtering walls and to ensure required velocity of flow of finely divided viscous suspension within the container.
Due to the above features, the apparatus according to the invention ensures greater degree of filtering and higher degree of dehydration of continuously fed flow of suspension, with continuous and reliable operation.